In the production of textiles it is frequently necessary to treat them with a gas so as to dye them, remove solvent from them, or simply dry the the textiles. In most manufacturing processes the textile is produced as an elongate web which is passed longitudinally through the various treatment stages, including the apparatus used to treat the textile with a gas.
In a known apparatus the textile passes straight in a horizontal line between a pair of spaced-apart parallel horizontal surfaces each provided with a plurality of nozzles to which air is supplied so as to form a gas cushion above and below the textile. This gas cushion supports the textile web as it moves longitudinally horizontally through the device and at the same time dries or fixes the textile, depending upon the function which the apparatus is to serve. The advantage of such a device is that the longitudinal and transverse tensions in the web are reduced to a minimum so that stretching or deformation of this web is almost completely eliminated. On the other hand such an apparatus has the considerable disadvantage that it occupies a great deal of floor space. In addition the web has a tendency to oscillate in a direction transverse to its transport direction, these oscillations potentially damaging the web which is frequently very weak in its wet state. In addition when the apparatus treats a relatively long piece of such a web the force necessary to pull it through, even though it is only floating on a cushion of air, is still considerable, especially when the web is wet.
It has been suggested to avoid many of these disadvantages by guiding the web positively by means of guiderails extending through the apparatus. This has been found extremely disadvantageous in that the access of the gas to the web is reduced in certain areas and the web is frequently damaged by the guide rails.
In another arrangement the web is gripped at its longitudinal edges by means of clips carried on a conveyor chain so that the web can be readily guided along a path, which in this case need not be horizontal but can be vertical, or, more efficiently, comprise a series of stretches which extend parallel to each other and allow the web to be passed through a path of maximum length which occupies a minimum amount of floor space. Such devices have the disadvantages that they are very expensive and frequently damage the web at its edges.